The Clinical Branch(CB), NEI uses images produced by the Scheimpflug principle to quantitate eye opacities. The principal goal is to find a technique to accurately determine changes in a cataract lens and to eventually observe the effects of anti-cataract drugs. CB/NEI employs Scheimpflug Slitlamp Cameras (SLC) to visualize pathological changes in anterior ocular measurements. A SLC measuring system consists of a s special photo slit lamp with a video or photographic imaging system. It is hoped that continued instrumentation development, image processing techniques and CSL's close work with NEI physicians will eventually lead to clinical trials of pharmaceuticals that may prevent or reverse the cataract formation process. NEI and CSL assistance continues to examine new SLC's as they are developed and become available. Although the SLC imaging systems used in the NEI Clinic have been modified to give the clinically useful information NEI desires, a commercial system which performs these operations as an integral part of the system would be purchased if it were available. Some of the basic requirements for a new SLC would include the ability to produce images which can be calibrated to optical densities, a wide dynamic range, operation at low light level, highly linear video system, distortion and achromatic free optics and the ability to save images in formats adaptable to NEI analysis programs. During the coming year, CSL will continue supporting NEI's cataract studies. Scheimpflug data from previous years will be analyzed using automatic region detection algorithms and the calibration of images to density values. Additional support for video signal acquisition and processing will be offered for Corneal Endothelium studies using a Keeler Specular Microscope, for Retroillumination imaging using an Oxford and Neitz camera system, and for 2D Gel analysis of lens proteins.